Inductor apparatus



AUS 7, i945. H. A. STRICKLAND, JR 2,381,43

INDUCTOR APPARATUS Filed Aug. 1l, 1943 2 Sheets-,Sheet l JNVENTOR Harold f7, ZPZUZa/zd Jn ATTORNEY Aug. 7, 1945. H. A. sTRlcKLAND, .1R 2,381,143

INDUCTOR APPARATUS Filed Aug. l1, 1943 2 Sheets-Sheet 2 liiii' NVENTOR A TTORNEY iatented yAug. 7, 1945 INDUc'roa APPARATUS narnia A. Strickland, Jr., Detroit, Mich., assignor to Budd Wheel Company, Philadelphia, Pa., a corporation of Pennsylvania .Application August 11, 1943, Serial No. 498,160

(Cl. 21S- 13) 8 Claims. This invention relates -to inductive heating apparatus and more particularly to inductive appaf ratus suitable for the heating and automatic iemoval of small ferro-magnetic plates or the ke. f

Among the objects of the invention are to provide means for heat treating a magnetic plate which is semi-automatic in itsY operation. Another object is to 4provide self-timing means in connection with the inductive heating oi' iron plates and the like. Still another object is'to provide a mechanism for heating small articles of uniform size and shape which may be continuously operated without modification of the electrical circuits involved. Additional objects include the provisionsof means for supporting off-center an object to be heated to facilitate gravitational displacement after the heating operation; the provision of heating means which includes self-centering means for rapid placement of the articles to be heated in heating position; the provision of heating means having a novel mode of support adjustment to permit variation in the center of mass of the article being heated with reference to the -supporting structure; and the provision of a heating unit having unusual simplicity of arrangement and limitation in number of parts.

Reference is made to -the following description for a disclosure of the invention, which may be preferred, and to the accompanying drawings, in which:

Fig. 1 is a front elevation oi' Ithe inductor unit;

Fig. 2 is a section along line 2-2 of Fig. 1;.

Fig. 3 is a plan section along line 3-3 off- Fig. 1; i

Fig. 4 is a. perspective oi the heating"unit showing the butler block in disengaged position; Fig-5 is a sectional detail along line 5-5 of Fig. 2 and Fig. 6 is a further sectional detail along line lof F18. 5.

Generally speaking, the simplified heating unit the same in a rigid unitary structure; and the buffer or holding block i1, likewise of insulation material, which is interposed between sections o the primary coil and in alignment with the vertical workpiece cavity to receive the shock of the irl-coming workpieceaand to assist in the supporting of the same during the heating operation.

Giving more detailed consideration to the struc-- ture, the two 'main guide blocks Iii and I2 are positioned vertically in parallel relationship as clearly shown in Figs. l and li, there being between these blocks a cavity i8, which is adapted. for the reception of the ilat metal workpieces in the heating operation. 'At the top of the structure the blocks I I and I2 are iixeclly spaced by means of the angled bridge plate I3 previously referred to. screws i9 serving to fasten the insulation blocks against the metal plate in fixed relationship thereto. v

The base sections of the blocks Ii and I2 are xedly spaced as in the upper section by means of the secondary unit i6. As clearly shown in perspective in Fig. 4, this secondary unit includes two U-shaped turns 20 and 2| of hollow cross section, each being square in its general outline and' combined in juxtaposition to form a single primary inductive element. The base end of these two turns 20 and 2| are combined in a single space 22 having a common opening 23 by means of which and the attached conduit 2i, connection is made to a source of liquid coolant as well as of electrical power. It is apparent by this construction that the turns 28 and 2| of the inductor unit are in parallel relationship both as to cooling and as to electrical conduction.

Secured to the turns 20 and 2| of the inductor unit are a number ot attachment plates and bars.

'At the top of turn 20 is fixed a cross bar 25 apertured at 26 to receive the holding screws 21 passing through the insulation blocks I| and I2.

Near the base ends ofA the primary turn 20 on I0 is comprised of ve elements, the upstanding and relatively massive guide blocks and I2 made of insulation materials'uch as asbestoscontaining compositions, and which form a substantial part of the structure; the top bridge plate Il whichfis right-angled including a hat top section I4 and vertical section I5 overlying the upper rear portion ofthe adjoining guide blocks II and I2 and secured thereto; the combined holding and vprimary induction unit Ilv which supplies the power to the workpieces and either side thereof are outwardly extending attachment bars 28 apertured at 29 to receive the holding scre'ws 30 also passing through the insulation blocks II and I2. To the outer turn 2| of the in'ductor adjacent the base of either arm also bridles the guide blocks I I and I2`to hold 56 of the turn are fixedly mounted lugs 3| and 32, the same extending rearwardly and being transversely apertured andscrew threaded to form adjustable pivot supports for the heating unit as a whole as will be more fully described hereinafter. On the arm of the induction -turn 2| which supports a lug 32 is also positioned rearwardly extending support rods 33 and I4, these rods being likewise apertured.

Adapted to be inserted in the space between lugs 3| and 32 and between the adjacent arms of the inductor unit is a buifer block |1. This block is roughly L-shaped and is provided with openings 35 and 36 adapted to register with the openings in the support rods 33 and 34 for the reception of holding screws 31 and 38, whereby `the buffer plate is held nrmly in position between and to the rear of the inductor coil. 'I'he lower enlarged section of the buler plate extends forwardly to form a ledge or shoulder 38 which ls inclined downwardly toward the forward face of the workpiece cavity. This inclined shoulder39 is adapted for the reception of the lower supporting end of Ithe workpiece when it is inserted in the workpiece cavity for heat treatment. An aperture 4U near the base of the block |1 is adapted i'or registry with the apertures formed in the lugs 3| and 32.

The unit as a whole is supported in any convenient manner as desired, depending upon therequirements of the particular manufacturing operation. A satisfactory support is as indicated in Figs. 1 and 2, in which parallel straps 4| and 42 are vertically positioned on supporting `plates 43 and 44 on a wall surface 45. The upper ends of each or these straps are formed with outwardly projecting lugs 46 and 41 transversely apertured to receive the bolts 48 and 49. The apertures of the lugs 46 and 41 and those of the lugs 3| and 32 are placed in alignment and the bolts 48 and 43 passing through Vthese apertures and making screw threaded engagement with lugs 3| and 32, serve to securely but adjustably attach the indoctor una la w the wsu support. n is noted that the lugs 3| and 32 of the Inductor unit are positioned within the lugs 46 and 41. of' the wall bracket as shown in Fig. 5.

It is pointed out further that the guide blocks Il and 2 are chamiered on the outer edges of the workpiece cavity so that a degree of tolerance is provided for the operator in the placing of the workpiece within the workpiece gap for heat treatment. It is also observed that the structure of the unit is such in relation to the workpiece that on the placement of the workpiece within the workpiece gap I3, the upper inner edge of the workpiece plate contacts with the metal of the y bridge plate I3, whereas the lower end of the workpiece engages the softer insulation substance of the butler block |1. Since usually rst contact is made at the upper endl ot the workpiece, since the bridge plate is further to the iront of the unit than the boiler block, the greater shock and,

wear oi' the apparatus is taken by the more resamt, mem of me bridge piste than the softer material ot the buffer block.,

In operating the apparatus as described. the workpiece in the shape, for example, o! a tank tread plate il is grasped by the Operator and rapidly inserted in the workpiece cavity Il as shown in Fig. 2 of the drawings, the uppeil portion of the plate engaging the bridge plate I3 and the lower portion engaging and seating on the ledge of the boiler plate I1. Electric power and cooling uuid having been previously'applied to the turns of the primary inductor Il, the electromagnetic eect or the inductor is to magnetize the ferro-magnetic material' of the workpiece plate Il at the point primarily of insertion within `the turns of the inductor coil and thus the workpiece plate is held firmly within the u nit irrelpective of the fact that the center of mus of the workpiece is substantially displaced outwardly from the point of support on the Aoiset ledge 3l of the -buier plate. The heating action continues until the section of the workpiece enclosed by the inductor coil is heated up to the temperature of recalescence, whereupon the magnetic holding effect disappears and the workpiece falls by grav ity into aquenching medium positioned directly beneath the unit or into a chute or conveyor, which carries the workpiece to a quenching medium. As soon as one plate falls from the heating unit, a second plate is inserted in the heating cavity to be held by the magnetic action oi the current. The heating process and automatic ejection of the workpiece is repeated as long as the operator desires.

The structure as described is, of course, subject to modification as to details, these being depend` ent upon the precise form of the workpiece and other variable conditions of operation, and hence no limitations are implied in the particular disclosure as made, the invention being compre hended within the following claims.

What is claimed is:

l. In an`inductive heating unit, a Combined workpiece retaining and heating coll, means lor guiding the workpiece into operative relationship to said heating coil, means `for arresting the movement of said workpiece in its movement through said coil at the point where the workpiece is in a state of unstable gravitational equilibrium and where a part only of said workpiece is subjected to inductive heating, and means for supplying electrical energy to said coil.

2. An electrical-inductive heating unit comprisingv a support, means for securing parallel insulation blocks to said support, said blocks being laterally spaced from each other to form a workreceiving cavity, a coil secured to said blocks on one side of said cavity, a stop positioned adjacent said coil to include the coil between itself and said blocks, said stop having a supporting ledge for giving partial support only to a workpiece insertable through said cavity into the coil area.

3. An electrical inductive heating unit comprising a support, means for securing parallel insulation blocks to said support, said blocks being laterally spaced from each other to form a work receiving cavity, a coil secured to said blocks on one side of said cavity, a stop positioned acijacent said coil to include the coil between itself and said blocks, said stop having a supporting ledge for giving partial support only to a workpiece insertable through said cavity into the coil area, and means for yadjustably mounting the unit formed by said support blocks, coil and stop.

4. An electrical inductive heating unit com prising asupport for said heating unit, two insulation blocks laterally displaced to form a workpiece heating cavity, a heating coil positioned on the rear side of said cavity, workpiece stops secured behind said cavity, and means for assembling said blocks, coil and stops on said support.

5. An electrical inductive heating unit comprising a support for said heating unit, two insulation blocksy laterally displaced to form a vertical workpiece heating cavity, a heating coil positioned on the rear-side of said cavity, upper and lower workpiece stops secured behind said cavity. and means for assembling said blocks, coil and stops on said support, said upper stop being positioned forwardly oi' said lower stop.

6, An electrical inductive heating unit comprising a support for said heating unit, two parallel insulation blocks laterally displaced to form a workpiece heating cavity, a heating coil positioned on the rear side of said cavity, upper and lower workpiece stops secured behind said cavity, and means for assembling said blocks, coil and stops on said support, said upper stop being constructed of harder material relative to said lower` stop, and said lower stop being constructed of electrically insulating material.

'7. An electrical inductive heating unit comprising a support for said heating unit, two insulation blocks laterally displaced to form a workpiece receiving cavity, a heating coil positioned adjacent the cavity to retain a workpiece 

